Radio
amateurs,
especially
those who
make QRP
transmitters
or
exciters,
are always
looking
for a
linear
amplifier
to get
more RF
Output.

I
made this
project
about 6
years back
and bought
plenty of
MRF455
from RF
Parts Co.
I made a
PTH PCB
and also
bought
necessary
Toroidal
cores from
Amidon. I
wanted to
make a
linear for
local QRP
group but
they never
completed
their
project.

Here
I have
place
technical
information,
Schematic
for this
project
with a
partial
kit made
available
in small
quantity
at lowest
possible
cost. Kit
cost
basically
comprise
of
transistors
&
Toroids. PCB is
supplied
free of
charge.

Schematic
& PCB
are based
on an
article in ARRL
Handbook 1981-3
detailing
MRF454
Linear
amplifier
construction
by K7ES.
In my PCB,
the change I
have made
is using a
DIP 723 in
place of G
package
which was
not
available
to me at
that time
and
include a
PTT
control by
way of a
PNP
switch.
Please
refer to
original
article
for more
details on
this
project.

More
details
are also
available
in
documents
given
below.

Partial
Kit:

Partial
kit contains
Toroidal
Cores from
Amidon,
2 pieces
of MRF455
and a PCB. I
have about
16 PCBs at
the
moment. I
bought
these
toroids
from
Amidon in
large
quantity
&
present
prices may
be bit
high. This
kits are
only
available
till my
stock of
cores
&
MRF455
clears.

Notes:

You may
use MRF454
on this
PCB since
original
design is
for
MRF454.
All
Toroids
are
suitable
for
handling
MRF454
Power
Levels.